Originally Posted by CanAutM3
I am not saying it is the case of your wheels, but simply looking at the wheel weight is not enough to assess if it will perform better on the dyno.
Rotational inertia (polar moment of inertia) varies with the square of the distance to which mass is located from the centre of rotation. So even if the wheel weighs less, if the mass is distributed farther from the centre, it could still have more rotational inertia.
I was agreeing with you
, it is however a special relationship between unsprung weight and rotational inertia which after all both depend on the mass of the wheel.